I was wondering if Daka is worth maxing out and if she is viable in arena?

The most frustrating squads I come across are Teebo Leads with Daka thrown in...sure that stun is great and all, but that -untargetable- Daka with rez feels like too much. Unless I get lucky and take Daka out before she goes invisible, and even before teammates like Rey & QGJ....which should go against all better judgement, it's the most futile fight ever.